1. Field of the Invention
The present invention relates in general to prison management and, in particular, to a system and method for tracking and monitoring prisoners using impulse radio technology.
2. Description of Related Art
The number of prisoners incarcerated in prison has increased dramatically in the past few years, resulting in an overcrowded and dangerous environment that is difficult for prison personnel to monitor and control. A prison typically includes an exercise facility, washroom, classroom, library, dining hall, workshop and housing unit. A majority of prisoners spend at least a portion of their time each day in each one of these areas of the prison. Of course, the prison personnel would like to keep track where each prisoner is currently located within the prison so that they can maintain the proper control over the prisoners.
To date many patents have been issued for various applications using Global Positioning System (GPS) to locate and track prisoners, parolees or people under house arrest. Various configurations of GPS-based tracking and communication systems and methods are described in the following patents, each of which is incorporated herein by reference: U.S. Pat. Nos. 5,182,566; 5,187,805; 5,202,829; 5,223,844; 5,225,842; 5,323,322; 5,243,652; 5,345,244; 5,359,332; 5,379,244; 5,382,958; 5,389,934; 5,390,125; 5,396,540; 5,408,238; 5,414,432; 5,418,537; 5,422,813; 5,422,816; 5,430,656; and 5,434,787.
All of the aforementioned tracking systems suffer from problems inherent with the use of GPS-based positioning systems. For instance, GPS based technology requires that each prisoner carry a relatively large GPS unit that is made up of GPS electronics, memory, logic, a R/F transceiver and a battery. As such, the GPS unit is not small enough to be conveniently carried by prisoner. Another problem with GPS units is that they suffer from certain well known inaccuracies such as the inability of GPS units located in a prison to effectively communicate with GPS satellites.
In addition to tracking prisoners, prison personnel also like to monitor the vital signs of prisoners. To date, multiple monitoring systems and methods that include electronic sensors for monitoring the vital signs (for example) of a prisoner have been described in various patents. A list of these patents follows, each of which is incorporated herein by reference: U.S. Pat. Nos. 6,054,928; 5,218,344; 4,816,377; 4,918,425; 4,918,432; 4,924,211; 4,943,885; 4,952,913; 4,952,928; 4,980,671; 4,999,613; 5,023,901; 5,032,823; 5,075,670; 5,103,474; 5,117,222; 5,146,207; 5,170,426; 5,182,543; 5,204,670; 5,206,897; 5,218,344; 5,255,306; 5,266,944; 5,298,884; 5,341,126; 5,369,394; 5,448,221; 5,455,851, 5,461,390; and 5,471,197.
All of the aforementioned monitoring systems that transmit monitored vital signs to another location suffer from problems inherent with the use of traditional communication systems. For instance, traditional communication systems are band limited and power limited which enables the transmission of only a limited number of monitored vital signs. In addition, traditional communication systems suffer from multipath interference which can be very problematic in a prison environment due to the closed-layout of a prison. Accordingly, there has been a persistent need to develop a system and method that can effectively track and monitor the prisoners within a prison.
The present invention includes a system, apparatus and method that utilize the communication capabilities and positioning capabilities of impulse radio technology to overcome the aforementioned shortcomings in conventional prison monitoring systems. Basically, the present invention enables prison personnel to track the movements of a prisoner and/or monitor the vital signs of a prisoner using impulse radio technology that is well suited for a prison environment.